KR100246706B1 - Ceramic sliding parts - Google Patents

Abstract

It is an object of the present invention to provide a sliding member that can prevent abnormal wear and uneven wear of counterpart metal sliding parts even when oil contaminated by exhaust gas components is used. The silicon nitride base material of the sliding surface material and the metal-bonded body having a larger thermal expansion coefficient than the sliding surface material are joined, and a crowning portion is formed on the sliding surface of the sliding surface material, and any axisymmetrical relation with respect to the center line of the crowning portion is formed. The difference in the amount of crowning (da, db) in two points is 10% or more and 50% or less with respect to the average value of two points of crowning amount.

Description

Ceramic sliding parts

Mechanical sliding parts represented by automobile engine parts often have convex crowning shapes on one side of a combination of sliding parts in order to prevent uneven wear and one-sided contact. For example, Japanese Patent Laid-Open No. 63-225728 discloses heat-bonding a wear resistant member having a smaller thermal expansion coefficient than a bonded base material on a sliding surface, and forming a crowning shape on the sliding surface by a thermal expansion difference. This discloses a manufacturing method which can provide a sliding part which can form a crowning shape without the machining of grinding | polishing etc., and can provide the sliding part which can prevent one side contact at the time of sliding at low cost. The patent also discloses the use of ceramic materials such as silicon nitride, silicon carbide, and cylon as wear resistant members.

On the other hand, recently, due to global environmental issues, tightening regulations on automobile exhaust gas are urgently required, and especially in diesel engines, emission reduction of NOx (nitrogen oxide) and P / M (particulate matters) is being considered. As a countermeasure, NOX reduction is being investigated by attaching an EGR (Exhaust Gas Circulation) mechanism to the engine exhaust machine.However, oil is contaminated due to chemical deterioration of the engine oil or P / M mixing from the circulation of the exhaust gas components. This causes a problem of abnormal wear.

In order to solve these problems, it has been proposed to form a gentle crowning, but this is not enough. For example, when a silicon nitride ceramic material having high abrasion resistance is used as the sliding surface material, the hardness is higher than that of the metal material as the relative sliding part. Therefore, when the crowning shape is deformed with respect to its center line, the contact surface or contact surface pressure when sliding This fluctuation occurs, in particular, fatigue wear such as partial wear, pitting and fretting of the relative sliding metal parts occurs.

The center line is a rotation axis when this sliding part rotates when it is used.

The present invention is to provide a ceramic sliding part having a crowning shape that does not generate the partial wear or fatigue wear.

The present invention relates to a tappet comprising a valve driving system part of an automobile engine, a sliding member such as a cam follower or rocker arm, and a sliding member disposed between an hydraulic circuit and a driving part in an engine, in particular a metal base material and a ceramic sliding member. When used for the piston of the hydraulic circuit using the drive system of the engine exhibits its utility.

1 is an explanatory diagram of a tappet and a cam of the valve drive system OHV method of a diesel commercial vehicle to which the present invention is applied.

2 is a partially enlarged view of the sliding member of the tappet to which the present invention is applied.

3 is an explanatory diagram (sectional view) of a tappet to which the present invention is applied.

4 is an explanatory view (sectional view) of a piston to which the present invention is applied.

5 is an explanatory view (sectional view) of a sliding part to which the present invention is applied.

6 is an explanatory diagram (sectional view) of a tappet to which the present invention is applied.

7 is a partially enlarged view of the sliding member of the tappet in the first and second embodiments.

8 is an explanatory view of the cam wear condition ((a) is a front view, (b) is a side view).

9 is an explanatory diagram (sectional view) of a tappet to which the present invention is applied.

10 is an explanatory view (sectional view) of a piston to which the present invention is applied.

11 is an explanatory diagram of the use status of the piston.

12 is an explanatory diagram (sectional view) of a tappet to which the present invention is applied.

FIG. 13 is an explanatory diagram of a metal body in Example 5. FIG.

<Description of the symbols for the main parts of the drawings>

1: sliding face material 2: cam

3: metal binding body 4: oil hole

5: joining surface 6: slider

7: lampshade 8: metal binding body

9: metal body outer peripheral sliding part (tappet)

10: concave sliding part (inner rod sliding part)

11: Metal binding outer circumference sliding part (piston)

12: piston 13: engine block

14 metal binding body (tappet) 14a: upper half of the metal binding body

14b: lower half of metal binding body

[Initiation of invention]

The structure of this invention for solving the said subject is a sliding component as described in the claim. In a sliding part in which a silicon nitride-based material is bonded to a sliding surface and a metal body having a larger thermal expansion coefficient than that of the sliding surface material, and a crowning shape is formed on the sliding surface of the sliding surface material, the axisymmetry is applied to the centering line of the crowning shape. The difference in the amount of crowning at any two points of is 10% or more and 50% or less with respect to the average value of the crowning amount of two points. This will be explained in the tappet parts of the diesel OHV engine shown in FIG.

In Fig. 1, the sliding face member 1 made of silicon nitride-based material is applied with a rotational force by a relative cam 2 sliding with a predetermined shift amount, and is rotated around the center line of the crowning shape of the sliding face member by rotating movement. The basic structure of the tappet parts that prevent one-sided contact is indicated. 2, the enlarged view of this sliding surface is shown. In this invention, the absolute value of the difference (da-db) of the amount of crowning da and db in arbitrary two points of axisymmetry, A, B with respect to the center line of the crowning shape shown in FIG. With respect to the average value of (da + db) / 2, it is necessary to satisfy the relationship of the following equation ①.

)접합가공의 경우에는, 경랍재두께의 균일화에 의한 정밀도향상 등을 생각할 수 있다)이나 특수한 기계가공(예를들면 크라우닝 형상정밀도를 전사한 총형다이아몬드연마석에 의한 NC연삭가공 등을 생각할 수 있다)이 필요하게 되고, 제조원가증대 등, 경제성의 점에서 문제가 있다. 또 이 제조원가에 비교해서 상대금속슬라이딩부재의 내마모성은 현저하게는 변화하지 않기 때문에, 소위 대가격성능비의 점에서 뒤떨어지기 때문에 바람직하지 않다.In this case, when the corresponding value exceeds 50% in equation ①, the contact surface and the contact area with the cam surface change during rotation, or the contact surface pressure fluctuates, in particular, uneven wear, fitting, fretting wear, etc. occur on the cam surface. not. On the other hand, in order to define less than 10% of the value, in order to secure the shape accuracy of the variation of the crowning, the improvement of the bonding precision (for example, ordinary meridians)

In the case of joining processing, it is possible to consider the improvement of precision due to the uniformity of the material thickness, and the special machining (for example, NC grinding processing by the total diamond abrasive stone transferred to the crowning shape precision). ), There is a problem in terms of economic efficiency, such as increased manufacturing costs. Moreover, since the wear resistance of the counterpart metal sliding member does not change significantly compared with this manufacturing cost, it is inferior in terms of so-called price performance ratio, which is not preferable.

In particular, since the lubrication conditions are severe in sliding parts, it is necessary to supply lubricating oil to the sliding part, and the oil hole 4 may be formed near the joint surface as shown in FIG. In this case, when an oil hole is formed in the metal body, the rigidity locally changes at that portion, and the crowning is deformed, so that the oil hole formed has a diameter d of the oil hole and a number n (n ≧ 1) of the oil hole.

1 is in the range of the metal body diameter D and ^{d 2 × n / D = 0.07~1.4} .

2. The total length of the metal binding body L and d ² × n / L is in the range of 0.05 to 1.05.

3. The maximum thicknesses W and d ² × n / W = 1.3 to 26 of the metal binding body where the oil holes are formed.

4. The relationship between the thickness t of the sliding members to be joined is in the range of d ² × n / t = 1 to 20.

5. it is preferred that the range of the relationship between the distance A to the oil hole from the center of the metal body joint surface ^{d 2 × n / A = 0.2~4.2} .

Below the lower limit of the range, the diameter of the oil hole becomes smaller, the viscous lubricating oil is less likely to flow, and the lubrication is impaired, and the abrasion or seizure of the metal binding body or the sliding member occurs, or the hole is formed. Machining becomes difficult, which is undesirable in terms of manufacturing cost. When the upper limit of the range is exceeded, the diameter of the oil hole is increased, and the rigidity of the metal binding part is partially changed, so that the crowning is deformed and the accuracy cannot be maintained, and the wear of the counter sliding metal parts occurs. The diameter and number of oil holes may be selected in a timely manner within the range specified in the present invention. When the oil holes are to be enlarged, the diameters and the number of oil holes may be adjusted to be near the upper limit of the range or by reducing the number. However, increasing the number of holes by reducing the hole diameter causes an increase in the manufacturing cost due to an increase in the number of steps when machining a hole even within a range, which is undesirable.

The oil hole may be formed either before or after joining the sliding surface material as long as the axial symmetry accuracy of the crowning obtained by forming the hole is within the scope of the present invention. Since it changes locally, it is more preferable to form before joining because it has a greater influence on crowning than forming before joining.

In the case where there are a plurality of oil holes 4, it is preferable to be at an equidistant distance from the joint surface 5 between the sliding surface material 1 and the metal binding body 3, but the equidistant distance is not necessarily affected if the crowning precision is not affected. No need to. The oil hole diameter may not be the same diameter without affecting the crowning accuracy. It is preferable that all the manufacturing phases are the same.

Moreover, this invention is achieved by the structure of a metal book body being two or more symmetrical with respect to the radial direction of a sliding surface. Since the crowning is formed by the balance of the rigidity of the bonded metal binding body and the sliding member, the crowning is deformed at the portion disturbing the symmetry if the symmetry is insufficient.

Therefore, when forming oil holes, it is more preferable to form two or more oil holes in order to maintain the symmetry of the metallic body.

The hole diameter and number should just be the scope of this invention.

On the other hand, in the case of the mushroom shape as shown in Fig. 4, such as a piston or a tappet of the hydraulic circuit, the diameter D2 of the slider portion 6 of the metal binding body 8 and the diameter D1 of the lampshade portion 7 are shown. It is preferable that the dimension ratio D2 / D1 of 0.5 to 0.5 or more, and the dimension ratio D2 / A2 of the slider portion diameter D2 to the freshest part thickness A2 of 6.5 or more. If D2 / D1 is less than 0.5, since the fresh flange of the metal binding body becomes large, the deformation is large and the crowning is not stabilized, and the axisymmetric accuracy cannot be maintained. It is more preferable that this dimension ratio exceeds 0.625. Since the metal binding body is mushroom-shaped, the upper limit is less than one. Even when D2 / A2 is less than 6.5, since the diameter of the slider portion is small, the fresh flange is large, as in the above case, and is not preferable. In addition, the shade part maximum thickness means the thickness from the joining surface with a sliding surface material to the point which becomes the same diameter as a slider part.

Since the length L1 of the slider portion is a sliding position, it is necessary to have a suitable length in function. However, if the length L1 of the slider portion is less than 10 times the maximum thickness A2, the rigidity of the metal body is small and the deformation is large, which is not preferable.

Although the shape of the part which connects a shade part and a slider part changes with the use condition of a sliding part, even if it is flat like FIG.5 (a) (b), it may be tapered. Pistons that use the lampshade as a stopper need to be flattened in FIG. 5 (a) or the like, and may be tapered if they are not necessary as in tappet FIG. 5 (b).

If the thickness A1 of the sliding surface material is less than 1 mm, the impact force applied to the sliding surface generated during the sliding exceeds the impact fracture strength of the sliding surface material and leads to destruction.

In order to obtain a stable deformation without generating a local change of rigidity, it is preferable that the metal binding body 8 is a single material and that joining such as welding or welding is not performed.

This is, for example, when the metal binding body is divided,

a. In the case of joining the metal binding body divided before joining the sliding face material, if the bonding nonuniformity occurs when joining the metal body, the thermal expansion / contraction of the metal body is partially uneven when the sliding face material and the metal body are brazed. The crowning partially deforms because it is done. In addition, the deformation occurring at the time of joining the metal binding body is released at the time of brazing, but since the deformation is also unevenly localized, the crowning partially deforms.

b. When joining the divided metal book body after joining the sliding face material, the deformation at the time of joining the lower half body 14b of the metal book body becomes uneven, and the crowning partially deforms.

c. In the case of joining dissimilar materials, in particular, when joining the sliding face material after joining the metal binding bodies, the thermal expansion coefficient between the dissimilar materials is different, so that the crowning deformation is partially uneven because the thermal expansion / contraction of the metal binding bodies during the brazing is partially uneven. .

From the above facts, even if the metal binding body is easily processed by the division and the manufacturing cost can be reduced, the characteristics required for the sliding member cannot be obtained, which is not preferable.

On the other hand, the selection of silicon nitride-based material as the sliding face material is compared to ceramic materials for other structural materials such as silicon carbide, aluminum oxide (alumina) and zirconium oxide (zirconia). The shape is formed stably, ② The strength is relatively high, and against the tensile stress generated when the crowning shape is formed, cracks do not occur during joining and after joining, and sufficient durability can be obtained. This is because three points of hardness and relatively high wear resistance are considered. Above all, the strength characteristics are important, and silicon nitride-based materials of 980 MPa or more, preferably 1274 MPa or more, are used as three-point flexural strength in accordance with JIS R1601 to prevent the above-mentioned problems, and to design the crowning shape (mainly The thickness of the sliding silicon nitride-based member, etc. can be considered).

As an example for providing the above-described crowning axial symmetry with low cost, as shown in FIG. 1 in addition to forming holes as described above, thermal expansion of the silicon nitride based material and the sliding surface material on the sliding surface 1 is shown. After joining the metal binding body 3 having a large rate, and forming a base crowning shape on the sliding surface in advance by the thermal expansion difference at the time of joining, the crowning shape is finished by grinding or glass abrasive grain processing. There is a method of processing and processing to the crowning precision shown in equation (1). When these methods are selected, it is preferable that the processing amount is 20% or less with respect to the maximum amount of crowning (for example, equivalent to dmax shown in FIG. 2) with respect to the center line of this crowning shape. If this exceeds 20%, the processing cost is large and there is a problem in terms of economical efficiency. In this case, it is necessary to form the crowning base shape precision in the joining step of the first step as desired. In addition, the material of the metal body is not particularly limited, but typical examples include JIS SCr, SCM, SNCM steel.

Moreover, as preferable side conditions for satisfying the effect of this invention, the surface roughness of the sliding surface of a sliding material is 0.4 micrometer or less as 10-point average height roughness prescribed | regulated by JIS. This is not preferable because it is possible to wear the relative sliding cam surface if it exceeds 0.4 µm as a 10-point average height roughness.

As described above, for example, the present invention can significantly prevent the wear of the ceramic sliding surface and the cam surface when used in an OHV type tappet among the sliding parts, and especially when applied to a diesel engine provided with an EGR mechanism. It is possible to significantly prolong the life of the parts.

Best Mode for Carrying Out the Invention

Example 1

From a commercially available silicon nitride, silicon carbide, alumina, and zirconia sintered body (shown in Table 1, three-point bending strength in accordance with JIS R1601), a disk-shaped material having a diameter of 30 mm and a thickness of 1.5 to 3 mm is cut out, and a surface sliding with a cam. For the polishing, diamond polishing stones having an average particle diameter of abrasive grains of 7 to 11 mu m were subjected to finish grinding so that the surface roughness was 0.3 mu m or less as the 10-point average height roughness. 6, a Ag-based solder material is used for the metal body 3 produced from the JIS standard steel material and SCr420 of the shape which displayed the sliding surface material 1 obtained as shown in FIG. It fixed with a jig and bonded at the temperature of the range of 790-880 degreeC for 1 hour in vacuum, and produced two types of tappet parts of 15 and 40 micrometers of target maximum crowing amounts. The total length of the metal body is 40 mm. The main body was carburized before hard soldering. After the bonding, laser quenching was used to quench the outer circumferential portion 9 and the inner bottom spherical recess 10 in the metal binding body. For some of them, the precision of the crowning shape was improved by an angular grinding process using a diamond abrasive stone having an abrasive grain average particle diameter of 7 to 11 탆. This part was embedded in a commercial OHV diesel engine for commercial vehicles, and the endurance test was performed for 500 hours at an engine speed of 1000 rpm using a recovery engine oil after 100,000 km of city driving, and the amount of wear on the cam surface was measured. . The above result was shown in Table 1. In Table 1, the shape precision of the crowning was expressed by a value obtained by substituting the above-mentioned formula ① for the amount of crowning d at a concentric circle of? 25mm with respect to the centering line of the crowning as shown in FIG.

On the other hand, for the determination of wear, the average wear amount before and after the test of the heights Ha, Hb, and Hc of the three points A, B, and C of the cam nose shown in FIG. [ha + hb + hc) / 3] and the deviation (difference between the maximum value and the minimum value of ha, hb, hc) and evaluated in the table. (A) is a front view of a cam nose, (b) is a side view.

In the display of the axisymmetric accuracy of the crowning shape in the table, "crack" indicates that the sliding member has cracked during joining. Therefore, engine evaluation was not performed with respect to the said material.

From the above results, it has been clarified that by using the sliding member made of silicon nitride material having a predetermined crowning precision, the wear amount and partial wear of the counter metal sliding parts can be significantly reduced as compared with the case of using other ceramic members. In addition, by using a material having excellent strength characteristics among the silicon nitride materials, it has become clear that the amount of wear and uneven wear of the counter metal sliding parts can be further reduced.

Example 2

Of the samples shown in Table 1 of Example 1, No. For 2, 4, 13, 14, 17, 19, 21, 23, 26, and 27, durability evaluation for 6000 rpm and 100 hours was performed with the engine similar to Example 1. Also about evaluation, the result of having evaluated similarly to Example 1 is shown in Table 2. FIG. Here, whether or not the sliding member was cracked was checked every 10 hours for 100 hours, and the time until cracking was indicated in the table. In the case of cracks, the amount of wear before that time is indicated in the table.

In the presence or absence of cracks in the table, "early cracks" are indicated for cracks already occurring after the first 10 hours. Therefore, the wear amount of this sample was not evaluated.

From the above results, it is evident that when a ceramic material other than silicon nitride material is used for the sliding member, cracking occurs initially in the high rotation region of the engine and does not contribute to practical use. In addition, by using a material having excellent strength characteristics among the silicon nitride materials, it has become apparent that cracking does not occur in the high rotational area of the engine, and wear amount and uneven wear of the counterpart metal sliding parts can be reduced.

Example 3

A commercially available silicon nitride (1) used in Example 1 was vacuum brazed at 870 ° C. with Ag-Cu-Ti alloy with a thickness of 0.05 mm, using the metal body 3 shown in FIG. 9 to prepare a tappet. did. The main dimensions of the metal binding body 3 are shown in Table 3. The inner sole spherical recess 10 has a diameter of 14 mm in Nos. 29 to 48 and a diameter of 9 mm in Nos. 49 to 57. The material used SCM435 (JIS G4105).

The oil hole connecting the opening and the outer circumferential surface was formed by machining by varying the diameter of the hole and the number of the holes by a distance A from the joining surface of the metal book body to the center line of the copper oil hole shown in Table 3.

Silicon nitride was processed to be 0.5 mm smaller than the metal body and the cam sliding surface was processed to less than 0.3 µm with a 10-point average height roughness.

After the joining, surface quenching was performed on the sliding portions (outer circumference portion and inner sole spherical recess portion) of the metal body. Specifically, high frequency quenching was performed on the outer circumferential portion 9, and electron beam quenching was performed on the inner sole spherical recess 10.

The measurement of crowning was performed similarly to Example 1. However, concentric circles to measure were 25.8, 20.8, and 14.2 mm when the outer diameters were Ψ31, 25, and 17mm. In addition, the crowning amount was 21-33 micrometers in NO.29-49, and 18-38 micrometers in NO.4900-57. The results are shown in Table 3.

In the table, NO.30, 31, 32, 33, 36, and 37 are incorporated into OHV diesel engines for commercial vehicles, and the engine is run for 200 hours at 1500 rpm using a recovery engine oil after 200,000 km. As a result of testing, NO.31, 36, and 37 showed the wear exceeding 50 micrometers in the outer periphery of a metal bound body. NO. 30, 32, and 33 are the average and the deviations of the wear amount of the cam nose shown in Example 1 when the wear was 5 µm or less. 14.3 mu m at 30 and NO. 32 at 12.3 μm, NO. 33 and 10, respectively.

No. At 36, the diameter of the oil hole was extremely small, so that the lubricating oil did not pass smoothly through the oil hole, and the sliding part with the engine block of the metal binding body was worn. However, since No. 36 is a tappet according to the present invention, the camnose wear amount and average deviation of the camnose shown in Example 1 are 10 and 2 µm, respectively, which are superior to those of the invention shown in Example 1, respectively. Was displaying. No. 31 and 37 are Nos. Compared with 36, the oil hole diameter was larger but the number of holes was small, so that the lubricant supplied to the metal body was insufficient, and wear occurred similarly.

Example 4

A commercially available silicon nitride 1 used in Example 3 was vacuum brazed at 950 ° C. with an Ag-Ti alloy of 0.07 mm in thickness, using the metal body 8 shown in FIG. 10, to prepare a piston. The main dimensions of the metal binding body 8 are shown in Table 4. The material used SCr440 (JIS G4101).

Silicon nitride was made to have the same diameter as that of the metal binding body, and the cam sliding surface was processed to 0.3 mu m or less as a 10-point average height roughness.

After joining, surface quenching was performed at a high frequency on the metal binding body outer peripheral part 11 which is a sliding part.

The crowning was measured in the same manner as in Example 1, and the concentric circles to be measured were φ25, 22.5, and 10mm in the case of the lampshade diameters φ30, 27, and 12mm. In addition, the crowning amounts were 79 to 95 µm, 62 to 83 µm, and 15 to 28 µm, respectively, in the case of φ 30, 27, and 12 mm. The results are shown in Table 4.

No. in the table 70-82 were incorporated into a commercial 6-cylinder OHV type diesel engine with a compression engine brake (exhaust rate: 11000 cc, and engine oil used 500,000 km in the city) and tested at an engine speed of 2200 rpm. The state which incorporated the piston 12 in the engine is shown in FIG. As a result of the test, the ceramic thickness was less than 1mm. In 70, 71 and 77-79, cracks occurred in silicon nitride immediately after the test. On the other hand 72 to 76 and 80 to 82 had no cracks in the silicon nitride even after the test, and the average and deviation of the wear amount of the cam nose shown in Example 1 were 8 and 2 µm, respectively.

Example 5

The tappet produced in FIG. 12 is displayed.

The sliding face material 1 processed the commercially available silicon nitride 1 used in Example 3 to 29.5 mm in diameter, and 2 mm in thickness, and the cam sliding surface was finished by grinding | polishing processing to 0.3 micrometer or less as a 10-point average height roughness.

The metal binding body 14

(1) First, the process is carried out in the shape as shown in Fig. 13A, and after the upper half 14a and the lower half 14b are joined, the sliding face member 1 is joined.

(2) Once, it processes to the shape as shown in FIG.13 (a), after joining the sliding surface material 1, and joins the upper half part 14a and the lower half part 12b.

(3) As shown in Fig. 13 (b), a single body is produced.

In the case of (1) and (2), the two types of the same case were produced by a combination of various materials. The metal binding body 14 has a diameter of 30 mm, an opening diameter of 26 mm, and an overall length of 39 mm. Specifically, it produced as shown in Table 5.

Joining of the metal binding body was performed by the method shown in Table 5.

The silicon nitride and the upper half portion 14a of the steel body were subjected to vacuum brazing at 850 ° C. with an Ag—Cu—Ti alloy with a thickness of 0.06 mm.

No. For 87 to 89, 91, 93 to 95, 98 and 100, high frequency quenching was performed on the sliding parts 9 and 10 at the time of tappet shape, and then incorporated into an OHV type diesel engine for commercial vehicles, and the city driving was carried out. The recovery engine oil after 100,000 km was run and the endurance test of 200 hours was performed at the engine speed of 3000 rpm.

No. 90, 97, 99, and 101 do not perform high frequency quenching because the used steel hardens during cooling.

No. 92 and 96 are the upper half portions 14a. Using the same steel material as 90 and the like, quenching was performed during brazing, and the lower half 14b, which had already been quenched after brazing, was joined.

The measurement of the crowning of each sample was the same as that of Example 3, and the concentricity to measure was set to (phi) 25mm. The precision of the crowning is shown in Table 5. In addition, the crowning amount was 15-32 micrometers.

As a result of the endurance test, No. In 87 to 97, the average amount of wear of the cam nose shown in Example 1 exceeded 50 µm, which is a practical problem. On the other hand, No. using a single material without bonding. In 98-101, the wear amount was less than half with 9-18 micrometers.

From the above results, it was confirmed that the tappet of the present invention produced from a single material without dividing the metal body showed excellent durability.

In addition, carburization in a table | surface shows the carburizing quenching in the divided shape, and a quenching material shows the thing which carried out oil quenching in the shape which divided similarly.

As described above, the present invention uses a silicon nitride material as the sliding surface member and has a specific crowning shape accuracy, thereby preventing abnormal wear of the counterpart metal sliding parts even when oil contaminated by the exhaust gas component is used. Thus, uneven wear can be prevented.

Claims (23)

A ceramic sliding part made of a silicon nitride-based material having a sliding surface and a metal-bonded body having a higher thermal expansion coefficient than the sliding surface material is joined, and a ceramic sliding part having a crowning shape formed on the sliding surface of the sliding surface material, wherein the center of the crowning shape part is provided. The difference in the amount of crowning at any two points of axisymmetry with respect to is about 10% or more and 50% or less with respect to the average value of the two-point crowning amount, and connects the inside and the outside of the body formed in the metal body to circulate the lubricant. A ceramic sliding part characterized in that the relationship between the diameter d of the oil hole, the number n of the oil hole, and the diameter of the metal binding body D is in the range of d ² × n / D = 0.07 to 1.4. The ceramic sliding part according to claim 1, wherein the structure (rigidity) of the metal binding body is at least twice symmetrical with respect to the radial direction of the sliding surface. 3. The ceramic sliding part according to claim 2, further comprising two or more oil holes connecting the inside and the outside of the body formed in the metal body to circulate the lubricating oil. The ceramic sliding part according to claim 1, wherein the whole metal binding body is made of a single material and a non-bonding material. A ceramic sliding part made of a silicon nitride-based material having a sliding surface and a metal-bonded body having a higher thermal expansion coefficient than the sliding surface material is joined, and a ceramic sliding part having a crowning shape formed on the sliding surface of the sliding surface material, wherein the center of the crowning shape part is provided. The difference in the amount of crowning at any two points of axisymmetry with respect to is about 10% or more and 50% or less with respect to the average value of the two-point crowning amount, and connects the inside and the outside of the body formed in the metal body to circulate the lubricant. A ceramic sliding part, characterized in that the relationship between the diameter d of the oil hole, the number n of the oil holes, and the total length L of the metal binding body is in the range of d ² × n / L = 0.05 to 1.05. 7. The ceramic sliding part according to claim 5, wherein the structure (rigidity) of the metal binding body is at least twice symmetrical with respect to the radial direction of the sliding surface. The ceramic sliding part according to claim 6, wherein the ceramic sliding part has two or more oil holes connecting the inside and the outside of the body formed in the metal body to circulate the lubricating oil. 6. The ceramic sliding part according to claim 5, wherein the entire metal body is made of a single and unbonded material. A ceramic sliding part made of a silicon nitride-based material having a sliding surface and a metal-bonded body having a greater thermal expansion coefficient than the sliding surface material is joined, and a ceramic sliding part having a crowning shape formed on the sliding surface of the sliding surface material, wherein the center of the crowning shape part is provided. The difference in the amount of crowning at any two points of axisymmetry with respect to is about 10% or more and 50% or less with respect to the average value of the two-point crowning amount, and connects the inside and the outside of the body formed in the metal body to circulate the lubricant. Wherein the relationship between the diameter d of the oil hole d, the number n of the oil holes, and the minimum thickness W of the metal body where the oil holes are formed is in the range of d ² × n / W = 1.3 to 26. part. 10. The ceramic sliding part according to claim 9, wherein the structure (rigidity) of the metal binding body is at least twice symmetrical with respect to the radial direction of the sliding surface. The ceramic sliding part according to claim 10, wherein the ceramic sliding part has two or more oil holes connecting the inside and the outside of the body formed in the metal body to circulate the lubricating oil. 10. The ceramic sliding part according to claim 9, wherein the entire metal binding body is made of a single material and a non-bonding material. A ceramic sliding part made of a silicon nitride-based material having a sliding surface and a metal-bonded body having a greater thermal expansion coefficient than the sliding surface material is joined, and a ceramic sliding part having a crowning shape formed on the sliding surface of the sliding surface material, wherein the center of the crowning shape part is provided. The difference in the amount of crowning at any two points of axis symmetry is 10% or more and 50% or less with respect to the average value of the two points of crowning, and connects the inside and the outside of the body formed in the metal body to circulate the lubricant. And a relationship between the diameter d of the oil hole and the thickness t of the sliding member joined to the number n of the oil holes is in the range of d ² × n / t = 1 to 20. The ceramic sliding part according to claim 13, wherein the structure (rigidity) of the metal binding body is at least twice symmetrical with respect to the radial direction of the sliding surface. 15. The ceramic sliding part according to claim 14, further comprising two or more oil holes for connecting the inside and the outside of the body formed in the metal body to circulate the lubricating oil. The ceramic sliding part according to claim 13, wherein the entire metal body is made of a single and unbonded material. A ceramic sliding part made of a silicon nitride-based material having a sliding surface and a metal-bonded body having a higher thermal expansion coefficient than the sliding surface material is joined, and a ceramic sliding part having a crowning shape formed on the sliding surface of the sliding surface material, wherein the center of the crowning shape part is provided. The difference in the amount of crowning at any two points of axis symmetry is 10% or more and 50% or less with respect to the average value of the two points of crowning, and connects the inside and the outside of the body formed in the metal body to circulate the lubricant. Wherein the relationship between the diameter d of the oil hole and the number n of the oil holes and the distance A from the joint surface of the metal body to the center of the oil hole is in the range of d ² × n / A = 0.2 to 4.2. . 18. The ceramic sliding part according to claim 17, wherein the structure (rigidity) of the metal binding body is at least twice symmetrical with respect to the radial direction of the sliding surface. 19. The ceramic sliding part according to claim 18, further comprising two or more oil holes connecting the inside and the outside of the body formed in the metal body to circulate the lubricating oil. 18. The ceramic sliding part according to claim 17, wherein the entire metal body is made of a single and unbonded material. A ceramic sliding part made of a silicon nitride-based material having a sliding surface and a metal-bonded body having a greater thermal expansion coefficient than the sliding surface material is bonded, and a ceramic sliding part having a crowning shape formed on the sliding surface of the sliding surface material, wherein the center of the crowning shape part is provided. The difference in the amount of crowning at any two points of axis symmetry is 10% or more and 50% or less with respect to the average value of the two-point crowning amount, and the slider portion in which the metal binding body is in sliding contact with the engine block and its one side. The shade portion has a shade portion at the end of the portion, and the sliding face member is bonded to the shade portion, and the dimension ratio D2 / A1 of the diameter D2 of the slider portion of the metal binding body to the diameter D1 of the shade portion is 0.5 or more, and the slider portion A ceramic sliding part, characterized in that the dimension ratio D2 / A2 between the diameter D2 and the freshest part thickness A2 is 6.5 or more. The ceramic sliding part according to claim 21, wherein the length (L1) of the slider portion is at least 10 times the maximum thickness A ₂ of the lampshade portion. The ceramic sliding part according to claim 21, wherein the thickness A1 of the sliding face material is 1 mm or more.

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